1. Dipartimento di Anestesia, Rianimazione ed Emergenza-Urgenza, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
2. Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
3. Department of Anesthesia and Intensive Care, IRCCS San Raffaele Scientific Institute, Milan, Italy
4. Vita-Salute San Raffaele University Milan, Italy
5. Department of Anesthesiology, Intensive Care and Emergency Medicine, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
6. Università Cattolica del Sacro Cuore, Rome, Italy
7. Università degli Studi dell'Insubria and Azienda Ospedaliera Ospedale di Circolo e Fondazione Macchi, Varese, Italy
8. Department of Anesthesiology and Intensive Care, ASST Fatebenefratelli Sacco, Luigi Sacco Hospital, Polo Universitario, University of Milan, Milan, Italy
9. DG Welfare, Lombardy Region, Milan, Italy
10. Department of Anesthesiology and Intensive Care, ASST Cremona - Ospedale di Cremona, Cremona, Italy
11. School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
12. Department of Anesthesia and Intensive Care Medicine, ASST Monza, Monza, Italy
13. Department of Anaesthesia and Intensive Care Unit, IRCCS San Matteo Hospital and University of Pavia, Pavia, Italy
14. Department of Anaesthesiology, Intensive Care and Perioperative Medicine, Spedali Civili University Hospital, Brescia, Italy
15. Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, University of Brescia, Brescia, Italy
16. Department of Anaesthesia and Intensive Care, ASST Papa Giovanni XXIII, Bergamo, Italy
17. Bruno Kessler Foundation, Trento, Italy
18. Department of Anesthesia and Intensive Care, Fondazione Poliambulanza Hospital, Brescia, Italy
19. Anesthesia and Intensive Care Medicine, Policlinico di Sant'Orsola, Alma Mater Studiorum University of Bologna, Bologna, Italy
20. Dipartimento Emergenza Urgenza, UOC Anestesia e Rianimazione, ASST, Lodi, Italy
21. Department of Anaesthesia and Intensive Care Medicine, Humanitas Clinical and Research Centre-IRCCS, Rozzano, Milan, Italy
22. Humanitas University, Milan, Italy
23. for the COVID-19 Lombardy ICU Network